Apparatus for orienting drilling tools



May 17, 1938. A. e. H. STRAATMAN APPARATUS FOR ORIENTING DRILLING TOOLSFiled May 19, ,1937

ll-lndex Rinq- /2- Upper Clamp 5Cr'e w 9 Telescope l6 lnvenfor:

fllphons Gerard Hubert fizfaaz man. By His Attorney; flandXkufl PatentedMay 17, 1938 Alphons Gerard Hubert Straatm an, The Hague, Netherlands,assignmto Shell Development Company, San Francisco, Calif., acorporation of Delaware- Application May 19, 1937, Serial No. 143,575 Inthe Netherlands May 22, 1936 4 Claims.

This invention relates to a method and apparatus for orienting varioustools and devices adapted to be lowered into a borehole on a string oftubing or pipe, such as deflecting wedges, whipstocks, knuckle 'joints,impression blocks, inclinometers, etc.

When orienting in a borehole any drilling tool of the above character,for example, a whipstock, the following procedure is commonly followed:

After securely attaching the drilling tool (whipstock) to the first(lowermost) pipe stand, suspended in the derrick, the drilling tool isgiven a known position in azimuth, which is considered as zero position.v

The pipe stand and the whipstock are then lowered into the borehole, andthe amount of rotation occurring with regard to said zero azimuthposition is determined every time another pipe stand is added to thestring.

For this purpose, it is customary to clamp to the upper portion of everypipe stand being added to the string a special device comprising twomembers: a stationary member rigidly attached to the pipe, and arotatable member carrying a sighting device. One of these members isusually. provided with a scale, and the other with an index, so that theamount of their rotation with.

, upper portion of the pipe stand is in the position formerly occupiedby its lower portion. The

amount and direction of the rotation of the pipe and of the drillingtool attached thereto occurring during this process can then be measuredby turning the rotatable member untilthe sighting device is againtrained on the reference point. After recording the rotationaldisplacement of the pipe, both members are removed from the pipe andattached to the top of the next pipe section being added to the stringand the operation is repeated. In order to minimize the loss of time,

two orienting devices, each comprising a stationary and a rotatablemember are commonly used in such operations. V

According to a modification of this method, the pipe string is returnedto its original directional position (zero azimuth) after lowering eachconsecutive pipe section by turning the string until the sighting deviceis again in alignment with the chosen plane of direction. This method ishowever relatively inaccurate and causes considerable delays owing tothe dlmculty of eflecting repeated rotational adjustments of the pipestring.

Both these methods have moreover the disadvantage that a reading has tobe taken and recorded after each consecutive pipe stand has been addedto the string and lowered into the borehole. This not only causes delay,but, because of the large number of readings required, results in urethe separate consecutive rotational displacements of a. pipe stringwithout the necessity of recording said measurements, and, second, toobtain automatically the algebraic summation of said separatedisplacements in order to obtain the total rotational displacement of apipe string, only a single reading being necessary after the finalmeasurement. This total rotational displacement may be determined withregard .to either a known initial position, or with regard to a positionto be determined, and the present orientation method may therefore beused either when lowering the pipe string (for example, in placing awhipstock), or whenraising the pipe string (for example, in'withdrawingan inclinometer or a core orienting device). It is obvious that in suchcases changes in the sequence of steps described hereinbelow may be madewithout departing from the spirit of the invention.

If, in order to save time, more than one orienting device is used, asdescribed below, the readings of the individual instruments will, ofcourse, have to be added up algebraically as the last step of theprocess.

The present method and orienting device will be better understood fromthe following description, taken with reference to the attached drawing,wherein:

Fig. 1 is a plan view of the present orienting device, and Fig. 2, across-sectional elevation view of the same device.

Referring to Fig. 1, the drawing shows a clamp-- of the measuring devicein a direction parallel to that of the pipe, and with a handle I.

The measuring device comprises the following parts, shown in both Fig. 1and Fig. 2:

(1) A sighting or aligning member 8, such, for example, as a telescope;

(2) A rotatable graduated scale member, such as a plate or ring ill, towhich the telescope is connected in fixed relationship by means of asupporting member or fork 9; 1 g

(3) A rotatable index member, such as ring I], concentric with androtatable with regard to said plate I0, and provided with an index markwhich slides along the scale of plate I when said plate and the ring I lrotate with regard to each other.

The scale plate Ill and the index ring H can be locked in fixedrelationship to each other by tightening the upper clamp screw I2 (shownin Fig. 1), which forces a friction ring I3 against a second frictionring l4, connected to index ring H, as shown in Fig. 2.

In turn, the index ring H is rotatable in the base l5, and can be lockedin fixed relationship thereto by tightening a lower clamp screw [6, Thebase I5 is secured to the tabular part 'l'l of the clamping member I bymeans of screws 2! and 22.

The telescope 8 comprises an objective l8 forming an image in the frontplane of an ocular I9 with engraved cross lines, and can be adjusted bymeans of a knob 20 at the base of the instrument. This ocular has theadvantage that the image can be observed at the normal visual distancewithout the eye being brought quite near the glass. The telescope ispivotally supported to allow for motion of its axis in a vertical planeup to inclinations of about 30 or more both upwards and downwards.

In practicing the method of the present invention the followingprocedure may be followed when using, for example, two devices of thetype described above:

The tool to be oriented is attached to the lower end of the first pipestand, and is suspended over the borehole in a chosen position. Forexample, a whipstock or a knuckle joint may be suspended so as to haveits plane of symmetry in the'direction it should have at the bottom ofthe bore-hole.

The indexmark of the index ring H of each measuring device is placedopposite the zero mark of the scale l0, and one of the devices isclamped to the top portion of the first pipe section. By loosening thelower clamp screw I6,

the index ring H is released with regard to the base l5, but remainslocked with regard to the scale In and to the telescope 8 connectedtherewith.

knob 20 until the line of sight is trained on a distant object, forexample, a ranging pole, both the scale In and the index ring llrotating together with the telescope. After'this alignment, the indexring is locked again by tightening the clamp screw I6. I

The first pipe section with the device attached thereto is then loweredinto the borehole until said device is near the derrick fioor. Anotherpipe stand is then added and the string suspended in the elevator, acertain amount of rotation unavoidably occurring during this operation,and the device rotating together with the string.

The upper clamp screw l2 of the orienting device -is then loosened, thescale it being thereby released with regard to the index ring M, the

ll again rotating with the telescope.

provided with steel jaws 6 for adjusting the axislatter, however.remaining locked in relation to the base IS. The telescope 8, togetherwith the scale I0, is then rotated with regard to the index ring II byan amount equal and opposite to the rotational displacement of thestring during the lowering thereof, until it is again trained on theranging pole. By tightening again the clamp screw l2 the rotation whichhas occurred is automatically registered as the displacement between themark zero on the scale 10 and the index mark on index ring II, and thenew setting of the orienting device may serve as the initial one for thenext measurement.

Meanwhile, the operator at the top of' the derrick attaches a secondorienting device to the top portion ofthe second stand. The lower clampscrew I6 is released and the telescope trained on the ranging pole, thescale l0 and the indexring After the clamp screw [8 has been tightenedagain, the first orienting device below may be removed from the pipe,and the string lowered throughout the length of the second stand. Inthis manner, the operator on the floor of the derrick manipulates onlythe upper clamp screw i2, and the operator at the top of the derrickonly the lower clamp scre'w IS, the possibility of errors being therebyminimized.

. This, cycle of operations is repeated until the whole string has beenrun in. The total rotational displacement of the tool attached to thelower end of the string is then obtained by taking the algebraic sum ofthe final readings obtained on each device separately at the end ofthe'whole series of operations. The orientation of the tool at the lowerend of the pipe string is then effected as fol- I lows:

is, the device is given its original setting. The

clamp screw l'6 is then released, and the telescope is -rotated togetherwith the scale In and the inindex mark on the index ring indicates onthe scale the total rotational displacement, that is, the

scope is again trained on the ranging pole, the

whipstock or other drilling tool being thereby brought into the desiredposition. The telescope 8 is then rotated by means of It is, of course,obvious that a drilling tool can be oriented by the present method whileusing only one orienting device, although such operation consumes asomewhat longer time.

In such case, the operations are carried out as follows:

The orienting device is attached to thetop of the first pipe stand, andthe telescope is trained on the ranging pole with the index mark on ringI l in register with the zero mark on the scale Hi. All clamp screws arethen tightened and the pipe stand lowered until the orienting device isnear the fioor of the derrick. The telescope is then' I device removedfrom the pipe, and hoisted on a cable to the top of the derrick, whereit is attached to the top of the second pipe stand. The telescope isthen trained on the ranging pole by releasing clamp screw IS, the indexring ll remaining at the same setting with regard to scale H) as it wasafter the sighting operation at the floor of the derrick. The secondstand is then lowered into the borehole, and the cycle of operationsrepeated until the whole string has been run in and the top of the lastpipe stand is near the floor of the derrick, the displacement of theindex mark on the ring I I with regard to the zero mark on scale Iautomatically giving the algebraic summation of the rotationaldisplacements of the string occurring as each pipe stand is lowered. Theclamp screw I 2 is then released, and the telescope rotated togetherwith the scale I0 until the zero mark on the latter registers with theindex mark on index ring II. The clamp screw I2 is then tightened againand the tubing string is rotated together with the orienting deviceuntil the telescope is in alignment with the ranging pole, whereby thetool at the end of the pipe string is given its desired position.

It is, of course, understood that the orienting method comprising thesteps of returning the pipe string to its original oriented position byrotating it after the addition of each separate pipe stand can equallywell be carried out by means of the present device.

I claim as my invention:

1. In apparatus for determining the orientation of a tool supported by apipe string for longitudinal motion within a borehole, an orientingdevice adapted to be rigidly clamped to the pipe, comprising a firstmember rotatable with regard to said device, a second member rotatablewith regard to said device and to said first member, and means forpositioning said rotatable members in known relationship to a desiredorientation plane, said rotatable members cooperating with each other toindicate the extent and direction of rotation of the pipe during thelongitudinal motion of the pipe within a borehole.

2. In apparatus for determining the orientation of a tool supportedby apipe string for longitudinal motion within a borehole, an orientingdevice adapted to be rigidly clamped to the pipe, comprising a firstmember rotatable with regard to said device, a second member rotatablewith regard to said device and to said first member, means forpositioning said rotatable members in known relationship to a desiredorientation plane, means for locking said first member with said secondmember, means for locking said second member with the device, saidmembers cooperating with each other to indicate the extent and directionof rotation of the pipe with regard to the desired orientation planeduring the longitudinal motion of the pipe within the borehole.

3. An orienting device for determining the orientation of a pipe stringwithin a borehole, comprising a body member adapted to be rigidlyclamped to the pipe, a scale member rotatably held by said body member,a sighting member supported in fixed directional relationship in ahori-- zontal plane by said scale member, an index member rotatably heldby said body member, said scale member and said index member beingrotatable with regard to each other, means for locking the scale memberwith the index member, means for locking the index member with the bodymember, said index member cooperating with said scale member to indicatethe extent and direction of rotation of the pipe with regard to thedesired orientation plane during the longitudinal motion of the pipewithin the borehole.

4. In the apparatus of claim 3, a sighting device mounted on the scalemember for pivotal axial motion in a vertical plane.

ALPHONS GERARD HUBERT STRAATMAN.

